Immunostaing of p53 associated with absence of mutations in TP53 gene in dogs with lymphoma

Sabendo-se da influência das mutações no gene TP53 no desenvolvimento das neoplasias e da discrepância entre os resultados obtidos pelas técnicas de sequenciamento e imunoistoquímica, esta pesquisa teve como objetivo relacionar a sequência do TP53 com a imunorreatividade da p53. Foram obtidas amostras de linfoma de 12 cães. O diagnóstico histopatológico foi determinado pela classificação de Kiel. O imunofenótipo e a imunomarcação da p53 foram determinados por imunoistoquímica. Para reação com a p53, utilizou-se anticorpo policlonal anti-p53 (CM1) na diluição de 1:500. A região do gene TP53 compreendida entre os exons quatro e nove foi amplificada por PCR e submetida ao sequenciamento. Apesar dos resultados obtidos pela imunoistoquímica, nenhuma mutação foi encontrada nas sequências analisadas. Conclui-se que a imunorreatividade da p53 pela imunoistoquímica não pode ser atribuída à presença de mutações no domínio central do gene TP53.TP53 mutations are usually involved in cancer, but sequencing and immunohistochemistry results are often controversial. Thus, the aim of this study was to associate TP53 sequence with p53 immunostaining in dogs with lymphoma. Tumor samples were collected from 12 dogs with lymphoma and were included in this study. Histopathological diagnosis was performed according to Kiel classification. Immunohistochemistry was performed to identify immunophenotype as well as p53 expression. Polyclonal antibody anti-p53 (CM1) was used at a 1:500 dilution. The region that encompasses exons 4-9 was amplified by f PCR reactions and sequencing was then performed. Nevertheless, gene mutations were not observed in any sequence. In conclusion, immunoreactivity of p53 by means of immunohistochemistry should not be indicator of presence of mutations in the core domain of TP53 gene

Paraneoplastic Hypercalcemia Secondary to Canine Mammary Tumors

Background: Paraneoplastic syndromes are complexes symptom that occur at a distinct site from the primary tumor or its metastasis by the production of hormone by the tissue in which the tumor appears. Paraneoplastic hypercalcemia is associated with an abnormal elevation of serum calcium levels and the mainly tumor related to this syndrome in canine is lymphoma, anal sac apocrine gland adenocarcinoma and multiple myeloma. In mammary tumors, the most frequent tumor that affect female dogs, this syndrome was also observed. The aims of this study were to evaluate serum calcium levels in female dogs with malignant mammary tumors and correlate calcium levels with clinicopathological parameters.Materials, Methods & Results: It was evaluated fifty-one female dogs with mammary carcinomas (simple carcinomas and carcinoma in mixed tumors) for serum calcium levels using colorimetric test. Clinical-histopathological data as spray status, pseudopregnancy, tumor size, ulceration, clinical staging, histopathological type and tumor grade were also evaluated in association with serum calcium levels. All dogs were treated with unilateral mastectomy. It was observed that 18 animals (35%) had calcium serum levels increased (>11.5 mg/dL) and 56% (10/18 cases) of these animals had serum calcium levels higher than 12 mg/dL. All dogs with hypercalcemia were asymptomatic, including two female dogs that presented the highest levels (13.43 mg/dL and 14.28 mg/dL). Hypercalcemia of malignancy was related to mammary carcinomas after the exclusion of other causes of hypercalcemia through laboratory tests (complete blood count and serum biochemistry) and abdominal ultrasound. No correlation was verified between the corrected serum calcium values with clinical and histopathological parameters evaluated.Discussion: In this study, it was observed a high incidence of paraneoplastic hypercalcemia associated with canine mammary tumors (35%). In humans, this syndrome is related in up to 10% of all patients with advanced cancer and with worse prognosis. The most frequent clinical signs of hypercalcemia are nonspecific and can be confused with other diseases, such as polyuria, polydipsia, anorexia, constipation, lethargy and weakness. The treatment of this syndrome is based on tumor resection and when necessary other treatments can be performed with fluid containing 0.9% sodium chloride, furosemide, prednisolone and calcitonin. Patients with asymptomatic or mildly symptomatic hypercalcemia (calcium levels <12 mg/ dL) do not require immediate treatment. Clinical signs occur more frequently with serum calcium levels higher than 15 mg/dL. Calcium levels higher than 18 mg/dL are considered a medical emergency and the clinical signs observed are trigger seizures, cardiac arrhythmia, acute renal failure and death. Most animals of this study presented mild hypercalcemia, that could justify the absence of clinical signs related to this syndrome, and the treatment for this syndrome was the tumor removal. The high serum calcium levels did not show correlation with more aggressive tumors and poorer prognosis, conditions evaluated by histological type, tumor grade and clinical stage. The evaluation of serum calcium levels is an important clinical test to be done in female dogs with mammary tumors, besides to be an affordable and technically simple test. The clinical signs related to this syndrome are nonspecific and may be confused with other diseases commonly observed in older dogs. The data suggest that there are no correlation between serum calcium levels with aggressiveness of canine mammary tumors and with other clinical features

Ovarian dysgerminoma causing multifocal metastases in young bitch

The ovarian neoplasias are unusual in canine species, mainly originated from germinative cells. Among these, dysgerminoma is a rare neoplasm in bitches, predominantly affecting senile and small and medium breeds. They are large, rounded, smooth surface, painless and firm in consistency. The clinical signs commonly demonstrated by patients with this neoplasia are abdominal distension and secondary signs of hyperestrogenism. The diagnosis should be based on the association of history, clinical signs, radiographic, ultrasonographic, cytological, histopathological and immunohistochemical exams. The treatment is the surgical castration and metastases are uncommon. Due to the rarity in bitches, specifically the young animals, this study aimed to describe a case of left ovarian dysgerminoma, of considerable size and adherence in adjacent organs, in a Brazilian Fila, whose showed considerable increase in abdominal volume and progressive weight loss. The diagnosis was confirmed by means of complementary x-ray, ultrasound, histopathological and immunohistochemical tests. Even with the recommended surgical treatment (castration), the patient demonstrated severe respiratory symptoms and increased abdominal volume after two months, and the complementary exams suggested pulmonary and multifocal metastases and the tutor chose euthanasia. As presented by the results, although rare in bitches, dysgerminoma should be included in the differential of ovarian neoplasias, including the young ones

Análise mutacional do gene supressor de tumor TP53 e imunorreatividade da p53 em linfomas caninos

Sabendo-se da influência das mutações no gene TP53 no desenvolvimento das neoplasias e da discrepância entre os resultados obtidos pelas técnicas de sequenciamento e imunoistoquímica, esta pesquisa teve como objetivo avaliar a sequência do TP53 e a imunorreatividade da p53, relacionando-as com fatores clínicopatológicos em cães com linfoma. Foram avaliados 12 cães com linfoma e cinco cães sadios. Amostras de neoplasia/linfonodo e de bulbo piloso foram obtidas. O diagnóstico histopatológico foi determinado pela classificação de Kiel. O imunofenótipo e a imunomarcação da p53 foram determinados por imunoistoquímica. Para a imunomarcação com a p53, utilizou-se anticorpo policlonal anti-p53 (CM1) na diluição de 1:500. A região do gene TP53 compreendida entre os exons quatro e nove (incluindo íntrons) foi amplificada por PCR e submetida ao sequenciamento. A média da imunorreatividade da p53 nos cães com linfoma foi 27,33%±12,14%, diferente da média do grupo controle (0,75±0,5) (P0,05). Apesar dos resultados obtidos pela imunoistoquímica, nenhuma mutação foi encontrada nas sequências analisadas...TP53 mutations are usually involved in cancer, but sequencing and immunohistochemistry results are often controversial. Thus, the aim of this study was to analyse both TP53 sequence and p53 immunostaining and to associate their findings to clinical-pathological features in dogs with lymphoma. Twelve dogs with lymphoma and five healthy dogs were included in this study. Tumor and hair sample was collected. Histopathological diagnosis was performed according to Kiel classification. Immunohistochemistry was performed to identify immunophenotype as well as p53 expression. Polyclonal antibody anti-p53 (CM1) was used at a 1:500 dilution. The region that encompasses exons 4-9 was amplified by means of PCR reactions and sequencing was then performed. p53 immunolabeling mean was 27,33%±12,14 in canine lymphoma group. It was statistically different from control group mean (0,75±0,5) (P0,05). Nevertheless, gene mutations were not observed in any sequence. In conclusion, p53 immunostaining is not essentially related to mutation in the gene TP53, particularly to the region between exons 4-9Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Cyclooxygenase Inhibitor Associated with Carboplatin in Treatment of Metastatic Nasal Carcinoma in Dog

A 10-year-old, intact male, pinscher was presented with unilateral bloodstained nasal discharge, sneezing, dyspnea, zygomatic arch deformity, submandibular lymph node increase, blindness in right eye, and exophthalmia. After clinical examination, it was found that the animal presented with upper respiratory tract dyspnea origin, possibly caused by an obstructive process. Complete blood count (CBC), ocular ultrasonography, thoracic radiographs, mandibular lymph node, and nasal sinus fine needle aspiration were performed. The right mandibular lymph node excisional biopsy was conducted and a tumor sample was obtained through the nasal fistula at hard palate. The material was processed, paraffin embedded, sectioned, and stained with hematoxylin and eosin. Immunohistochemical staining for cytokeratin (AE1/AE3), vimentin, and COX-2 was performed. After histopathological evaluation nasal carcinoma diagnosis was obtained. Chemotherapy was established with carboplatin 300 mg/m2 intravenously—four cycles with intervals of 21 days—and firocoxib 5 mg/kg orally every 24 hours for 7 months. After 7 months the treatment started, the animal presented with ataxia, vocalization, hyperesthesia, and anorexia. Due the clinical condition presented, the animal owner opted for performing euthanasia. The chemotherapy protocol was effective causing the disease stagnation, minimizing the clinical signs, and extending patient survival and quality of life

Canine prostate: would the dog be an important model for the study of new drugs?

Prostate cancer is ranked as the second leading cause of cancer-related death in men aged above 50 years and the long-term survival of patients with metastatic disease has not changed significantly. This fact is related mainly to the limited therapeutic options available. Despite numerous studies on PCa in humans, succes was not obtained in clinical trials of targeted therapies because of the difficulty in standardizing an ideal animal model for application in clinical trials. The use of dogs as a model for the clinical trials of new drugs can bring in higher accuracy in assessing the response of tumors to the drugs tested, with the assumption that the dog is a natural model of the disease and shares the same environment as humans. Due to the importance of prostate carcinoma in man the goal of the review is to identify the strengths of the dog as a model fot the development of new therapy for prostatic carcinoma

Nodular dermatofibrosis in a gentian shepherd dog: case report

An 7-year-old male German shepherd dog not neutered was attended presenting several cutaneous nodules ranging from 0.5-3 cm in diameter at least a one year history, located mainly in thoracic and pelvic limbs, with progressive weight loss over two months. Fine needle aspiration biopsy and pelvic and thoracic limbs nodules excision biopsy were performed. After histopathological diagnosis, nodular dermatofibrosis diagnosis was determined and abdominal ultrasound was performed for possible renal cysts evaluation. The animal received treatment to control secondary bacterial infection. It is necessary to carry out histopathological examination and ultraosund to identify possible renal cysts and for definitive diagnosis. There is no specific treatment for nodular dermatofibrosis. © 2013 Asian Network for Scientific Information